This invention relates generally to a surgical apparatus, and a procedure and method for using that apparatus. Light sources used in surgical procedures include illuminating light sources for visualizing structures and targeting laser light sources for intraoperative aiming, marking, or aligning. Illuminating light sources may be ceiling-mounted, surgeon head-mounted, instrument-mounted, or handheld.
Light from ceiling-mounted light sources can be blocked from illuminating the surgical site by the bodies of the operators and by instruments. Surgeon head-mounted lights avoid this problem of body blockage but instrument blockage can still be a problem. Also the surgeon must maintain a fixed head position in order to direct light into the wound while trying to operate. Further, adjustment of a head-mounted light can be cumbersome, requiring the surgeon to stop operating while a nurse adjusts the non-sterile head mount.
The surgeon can experience discomfort from a tight head mount during long cases. Instrument-mounted lights avoid many of these drawbacks. But the advantages are lost when an instrument with a fixed mounted light is replaced by an instrument without a light. Also, a fixed instrument-mounted light may still not direct the light at the desired area in the surgical field.
A handheld light overcomes these drawbacks. Such a light can be detached from one instrument and re-attached to another, and can be used without attachment to an instrument. It can be aimed where desired.
Along these lines, targeting light sources including but not limited to lasers, may be mounted to instruments such as saws or drills to guide their point of application. They may be mounted to x-ray machines to align the x-ray beam with the anatomy before radiating the patient. They may be used independently to mark locations for incisions or points for application of instruments. Targeting laser light sources may be mounted to instruments such as saws or drills to guide their point of application. They may be mounted to x-ray machines to align the x-ray beam with the anatomy before radiating the patient. They may be used independently to mark locations for incisions or points for application of instruments. They may be used to properly align surgical instruments or surgical implants.
Targeting laser light sources may be mounted to instruments such as saws or drills to guide their point of application. They may be mounted to x-ray machines to align the x-ray beam with the anatomy before radiating the patient. They may be used independently to mark locations for incisions or points for application of instruments.
Power sources for illuminating light sources or targeting laser light sources can be wall-powered or battery-powered. Wall-powered light sources have the advantage of supplying large amounts of power for an indefinite period of time. The main disadvantage of wall-powered light sources is the requirement for power cords or fiber optic cables. These cables connecting a head-mounted light to a power source restrict the surgeon's mobility, such as when moving to the opposite side of the table or out of the way of an x-ray machine. For illuminating light or laser light sources located on the operative field, there are also disadvantages. The cables must be sterilized. They must be attached to the patient's surgical drapes on one end and the other end passed off the sterile field to the power source.
These cables restrict the mobility of attached and non-attached instruments used during the procedure. The cables restrict the movement of operating personnel and machines around the patient. The cords can be tripped over or caught by machine movement, dislodging the surgical drapes to which they are attached.
Battery-powered light sources overcome these cable-related disadvantages. Since they act within the sterile field, battery-powered light sources require a sterile enclosure for the non-sterile light source and battery.
Further, the light source and the battery may be in separate enclosures, where metal contacts can penetrate each enclosure. Attaching the two enclosures can join these contacts. This configuration is used with surgical devices that consume a large amount of power, such as drills. The separate battery enclosure can contain rechargeable batteries. Separate recharged battery packs can be sterilized and kept on the sterile field to replace battery packs attached to the drill when those packs become discharged.
Battery-powered illuminating and targeting laser light sources consume relatively low amounts of power, eliminating the need to replace batteries during the course of a surgical procedure. Both the light source and the battery are typically contained in the same enclosure which may be reusable.
The empty enclosure is sterilized as follows. The sterile surgical assistant holds the opened enclosure while a non-sterile nurse drops the non-sterile light source and battery into the enclosure. The sterile surgical assistant then closes the enclosure, such as by screwing a sterile cap or lid onto the enclosure.
One disadvantage of this arrangement is that sterility can be broken by contact between sterile and non-sterile components or personnel as the enclosure is being loaded and sealed. Furthermore, drop-in light sources may require alignment adjustments after being placed in the enclosure.
Enclosures for light sources also require a transparent area on the lens in order to allow the light beam or laser beam to exit the enclosure. Sterilization of a reusable enclosure may leave moisture in the enclosure. This moisture can be heated by the light source, causing condensation on the lens, which in turn impairs light transmission through the lens. Overcoming this problem can require attaching a suction line to the case and providing a vent opening in the case. This suction line would result in the disadvantage of having another tube to pass off the surgical field, causing the same problems as with power cords. The vent opening also makes the enclosure less water-tight and therefore limits the sterile integrity of the case in some situations.
Thus, a single-use, disposable, pre-sterilized battery-powered illuminating or laser light source such as within the embodiments disclosed herein avoids these problems. The light source and battery are placed in the enclosure. The light beam is adjusted. The enclosure is permanently sealed and then sterilized. Condensation in the case is avoided. No sterile breach can occur in loading. No vent opening in the case is required. With light source and battery contained in a sealed enclosure, provision must be made for a means to switch the power on and off. Several types of switches are available to connect and disconnect the battery to the light source. These include membrane, push-button, and toggle switches.
Membrane switches require some portion of the enclosure to be made of a flexible material such as a thin plastic or rubber. Depressing the flexible area of the enclosure depresses the underlying membrane switch. Disadvantages include possibly cracking or puncturing of the plastic or rubber and difficulty in achieving a waterproof seal where the flexible and rigid sections of the enclosure join. These problems can result in contamination of the sterile field by fluid penetrating the enclosure, contacting non-sterile components, and then exiting the enclosure. Moisture in the enclosure can also obscure the lens and impair operation of electrical components.
Push-button and toggle switches penetrate the enclosure. Typically O-rings or gaskets and mounting nuts are used to seal between the enclosure and the switch body. Push-button switches typically use a rubber membrane to seal off the switch case itself. This thin membrane flexes as the button is depressed. The rubber membrane can crack or puncture or lose seal to the switch case. The same problems can occur in push-button switches as with membrane switches. Toggle switches typically rely on an O-ring around the arm of the switch to seal off the case itself. This O-ring seal can leak, particularly if subjected to sufficient water pressure. The O-ring is more prone to leak while the switch is being moved between on and off positions than when it is stationary. These switches can be subjected to high water pressures due to their proximity to the surgical field during wound irrigation, particularly when powered irrigation is used. In some instances these illuminating lights or targeting laser lights may be used in body cavities and therefore may be subject to total immersion.
Next, electrical Switches are designed with various capacities to resist ingress of solid and liquid material. Test procedures and rating scales have been standardized for ingress protection. Enclosures can be rated in order to prevent ingress by solids as large as a finger, to as small as dust. Enclosures can be rated in order to prevent ingress by moisture as limited as being sprayed from one direction, to being sprayed from all directions, to being submerged up to one meter, or being submerged more than one meter. It is desirable to improve on the ingress protection capacity of switches used with single-use, disposable battery-powered illuminating or targeting laser light sources.
As battery-powered light sources become smaller, their usefulness increases. With a smaller size, these devices offer less obstruction of the operating corridor or wound. This is particularly true as minimally invasive procedures require smaller, more restricted incisions. Smaller size allows these devices greater access to body cavities. The size of these devices is determined by the size of the light source, the battery, and the switch. It is desirable to reduce the size of the switch in order to reduce the overall size of the enclosure.
The material discussed in this Background is included for context only. None of the remarks in this Background should be construed as an admission of prior art.